BUG: Fix previous_codecs sharding_codec addition

Using the append() method returns None, which results in sharding_kwargs['codecs'] being set to None instead of a list containing the new codec. Consider replacing this with 'previous_codecs + [sharding_codec]' or appending to previous_codecs and then assigning it directly.

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: thewtex

ngff_zarr/to_ngff_zarr.py

@@ -317,7 +317,7 @@ def to_ngff_zarr(
                 sharding_codec = ShardingCodec(chunk_shape=c0)
             if "codecs" in kwargs:
                 previous_codecs = kwargs.pop("codecs")
-                sharding_kwargs["codecs"] = previous_codecs.append(sharding_codec)
+                sharding_kwargs["codecs"] = previous_codecs + [sharding_codec]
             else:
                 sharding_kwargs["codecs"] = [sharding_codec]
             arr = arr.rechunk(shards)